K+-stabilized nanostructured amorphous manganese dioxide: excellent electrochemical properties as cathode material for sodium-ion batteries

• Published in: Ionics Vol. 27; no. 4; pp. 1559 - 1567
• Main Authors: Wang, Ruiqi, Chen, Tong, Cao, Yongjie, Wang, Ning, Zhang, Junxi
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-04-2021; Springer Nature B.V
• Subjects: Amorphous materials; Cathodes; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Electrochemical analysis; Electrochemistry; Electrode materials; Energy Storage; Manganese dioxide; Optical and Electronic Materials; Original Paper; Rechargeable batteries; Renewable and Green Energy; Sodium-ion batteries; Structural stability; Transition metal oxides; Excellent electrochemical performance; Amorphous MnO; Potassium ion doping
• ISSN: 0947-7047; 1862-0760
• DOI: 10.1007/s11581-020-03880-3

Various transition metal oxide materials like MnO
2
have been reported as cathode for sodium-ion batteries. However, the large sodium-ion radius and migration barrier cause its poor structural stability and low electrochemical performance. Herein, we present a simple pre-potassiation way to stabilize the nanostructure of amorphous manganese dioxide (a-MnO
2
). The pre-potassiation amorphous manganese dioxide (K-a-MnO
2
) heating treatment at 400 °C manifests outstanding electrochemical properties in the aspect of specific capacity and cyclic stabilization, the reversible specific capacity maintains at 180.8 mAh g
−1
after 200th cycles under a current density of 0.1 C, and it shows a rate capability of 178.2 mAh g
−1
, 157.5 mAh g
−1
, 120.8 mAh g
−1
, 95.5 mAh g
−1
, 71.4 mAh g
−1
, and 47.1 mAh g
−1
at 0.1 C, 0.2 C, 0.5 C, 1 C, 2 C and 5 C, respectively. The findings exhibit that the pre-potassiation way can stabilize the structural of a-MnO
2
and effectively improve its electrochemical performance.
Graphical abstract
The pre-potassiation amorphous manganese dioxide (K-a-MnO
2
) heating treatment at 400 °C shows a reversible specific capacity maintains at 180.8 mAh g
−1
after 200th cycles under a current density of 0.1 C with a high structure stability.